Electric water-heater



H. A. MUEVANY AND H. E. KENNEDY.

ELECTRIC WATER HEATER. APPLECAUON FILED Nov.21.1s18.

1,323,643. l Patented Dee. 1919.

ATTORNEYS Unir-ED s'rnrns PATENT onirica.

HARRY A. MULVANY AND HARRY E. KENNEDY. GF BERKELEY, CA'LIFRNIA, ASSIGNORS TO ELECTRIC' SALES SERVICE CO., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION F CALIFORNIA.

cheaply manufactured e ectric water heater l` which is particularly adapted for use in standard house boilers and the `like and which is so constructed `that'it may be installed Without changing the pipe connections or` altering the boiler in any manner.

Another object of the invention is to provide an electric heater which permits slight expansion and` contraction With. current changes, thereby producing a self-cleaning action, as all scale and any precipitate which would otherwiselaccumulate and lower the efficiency of the heater, is cracked off.

Another object of the invention is to provide a novel mounting for the heater and `terminal box employed in connection therewith, and also to providemeans for preventing leakage between the heater and the terminal box.

'Further objects Will hereinafter appear. The invention consists of the parts and. the construction, combination and arrangenientiof parts as hereinafter more fully de-A scribed and claimed, having reference to the accompanying drawings, in which- Figure 1 is a side elevation of a water boiler partly broken away, showing the application of the invention.

Fig. is an enlarged central verticalsection' through the heater and the terminal box. Fig. 3 is a cross section on line 3 3,

rar. '2.

Referring to the drawings iii detail. A indicates a standard form of water boiler and 2, 'the Vdrain openingl through' which accuniulating mud and scale is generally removed. Adaptedv tohe screwed into the drain opening is a T-{itting 3.' 'l`his litting is i'iroif'idedii-n the i'ircsent instance as a siip port for the electric water heater generally` indicated at B and also as a support for the terminal box C of the heater. The

ELECTRIC WATER-HEATER.

Patented Dec. 2, i919;

ppiieaeion ined Nsve'mber 27, 1918. semina. 264,426.

heater proper consists of a double-walled tube B, which is split,'as shown at 4'; to, permit expansion and contraction of the tube, due to hea't variations, and also to form coininunication between the interior and the cxterior of the tube. Mounted between the double` walls of the tube'is a plurality of heating elements 5, of suitable construction. These elements are insulated .from each other and also from the walls of the tube, to prevent shorbcircuiting of the individual ele-merits. The upper end of the tube or the double walls of which it is formed, is closed as at 6 to prevent `admission of water while the 4lower 'end of the tube is open as shown at 7 to permit the terminal ends of the heating elements to pass out of the tube and into thc'terii'iiiial 'box C, each wire being .connected to the respective terminal screws 8,/,as shown, to permit the formation of the circuits desired; The number of terminal screws employed will depend entirely upon the number of separate elements placed Within the tube and it is therefore obvious that as many terminal screws are provided 'as conditions may demand.

The heater consistingr of the tube shown and the elements mounted therein, is secured in the T-litting 3 by means otathrcaded bushing E), the tube being soldered or otherwise secured to the bushing to prevent leakage between the bushing and the tube and also to secure the tube. rigidly iii the bushing. For the `purpose ot preventingr leakage down through the center portion l() of the tube anfl into the terminal box, we provide a pair of plugs such as shown at 1]. and 12. Both plugs are soldered within -tlie tube and thereby form a double seal which positively prevents .admission of water to the terminal box C. Leakage, if any, that might escape by the bushing 9 or the plug 11 would merely drop on top of the terii'iinal box and run ofas the plug 12 would positively vprevent Water from leaking by this point as the water once escaping by the plug 'll'would not be under pressure and would tl'icrefore escape in the path o'f'least resist.- ance offered. The T-litting is provided with a removable plug which permits any mud or accumulating scale to be flushed out from time to time., free escape of water vand mud being possible at all times as water cannot only enter through the upper end of the tube butl also through the slot 4f. This l sure has free admission to all points. A

heater constructed as here shown, has proven ,very efiicient iii-'constant service as it presents a large heating surface, dueto the @et that the water to be heated comes in contact not only with theexterior but also with the interior surface of the tube. It is al'so eilicient, due to the fact that the split in the tube permits it to contract and expand with temperature variations, thereby'A producing va self-cleaning action as it positively cracks oii' scale or otherprecipitants contained in 'the water?4 A f Another feature ofthepresent invention is the vsimplicity of construction which per- .l mits it to/be cheaply manufactured and readily installed. In fact,."any ordinary I plumber can' make the installation as it -is only necessary to remove the'old drain plug and insert the T-fitting contaiziin the heater tube and the terminal box, as s own.

While the'heating tub'e is here shown as being perfectly circular in. cross xsection, it is .obvious 'that -the shape may be varied to suit different installations; similarly, that the number of heating elements and the construction of same may. be varied and also that the materials and finish of the other ,parts employed 'may be such as the experience and judgment of themanufacturer may dictate ."Having thus described our invention,

A what we claim and desire to secure by Let- -ters Patent is y1. In an electric water heaterga fitting having an upper end formed to be screwed into the drain opening of a water boiler, a

heater extending through the fitting and below the lower end thereof, and aterminal box secured to the lower end of said heater,

said heater having its upper end projecting heaterextending through the'vertical leg of the fitting and above said Aupper end thereof and into the boiler and also extending below the lower end of the vertical leg of the fitting and a terminal box on said lower end of the fitting, the lateral arm of the T-litting extending below the boiler and having a removable drain plug.

3. An electric water heater comprising :i T-pipe fitting adapted to be screwed into the drain opening of a water boiler, a doublewalled tubular heater extending through the T-ittingand secured therein, a plurality of heating elements disposed between the double walls of the tube and insulated therefrom, a terminal box secured on the lower end of the T-itting, and a sealing plug 1` within the tube adapted to prevent leakage 'between the T-fitting and the terminal box. 4. .An electric Water heater compri'sim a T-pipe fitting adapted to be screwed into the drain opening of a water boiler, a double-walled tubular heater extending through the T-itting and secured therein, a plurality of heating elements disposed between the double walls of the tube and insulated therefrom, a terminal box' secured on the lower end of the tube and spaced 'belowy the lower. end of the T-iitting, a sealingi'plug within the tube adapted to prevent leakage between the T-fitting and the tei-mir ll box and la second sealing plug in the lojir end of the tube. 'i .i Y y 5. An electric water heater comprlsing a T-pipe fitting adapted to be scieiwd into the drain opening of`a water boilei, n double-walled split tube extending through the T-tting and secured therein, a sealing plug in the lower end of said tube, a second sealing plug mountedv below the first named sealing plug, a terminal boasecured on the extreme lower end of the tube ar a plurality of heating elementsl disposed between the double walls ofthe tube and insulated therefrom. p

Ln testimony whereof we have hereunto above the upper end of the fitting wherebyoY set our hands in the presence of two subupon screwing of the latter into the boiler the heater will extend into the boiler interior.

2. In an electric Water heater, a substantially T-shaped fitting having its upper end threaded s o as to be capable of being screwed into the drain opening of a water boiler, a

scribing witnesses.

HARRY A. MULVANY. HARRY E. KEHNEDY, i Witnesses:

' WV. W. HEALEY,

M. E. EWING. 

